3. In a study to test whether there is a difference between the average height of adult females born in two different countries, random samples yielded the following results:
n1 = 120, 1 = 62.7, s1 = 2.50
n2 = 150, 2= 61.8, s2 = 2.62
where the measurements are in inches. Use 0.05 level of significance to test the difference between the average heights.
4. Write short notes on:
(a) The F- distribution
(b) Auto-Regressive (AR) models.
5. Find the area under the standard normal curve, which lies
(a) to the left of z = 0.94
(b) to the right of z = – 0.65
(c) to the right of z = 1.76
(d) between z= – 0.34 and z= 0.62